What does a wattmeter measure?

A wattmeter is specifically designed to measure electrical power in watts. This instrument calculates the power consumed by a circuit by applying the voltage and current values and taking into account the phase difference between them in AC circuits. The primary function of the wattmeter is to provide a direct reading of power, which is essential for assessing the efficiency and performance of electrical systems.

In contrast, other instruments measure different electrical parameters: resistance is measured in ohms, voltage in volts, and current in amperes. Each of these measurements serves its own purpose in electrical diagnostics and analysis, but a wattmeter's unique role is to quantify the power consumption of an electrical device or circuit. This capability is crucial for evaluating energy usage and ensuring that electrical loads operate within their rated power limits.